Class HtmlCleaner


  • public class HtmlCleaner
    extends java.lang.Object
    Main HtmlCleaner class.

    It represents public interface to the user. It's task is to call tokenizer with specified source HTML, traverse list of produced token list and create internal object model. It also offers a set of methods to write resulting XML to string, file or any output stream.

    Typical usage is the following:

    // create an instance of HtmlCleaner HtmlCleaner cleaner = new HtmlCleaner(); // take default cleaner properties CleanerProperties props = cleaner.getProperties(); // customize cleaner's behavior with property setters props.setXXX(...); // Clean HTML taken from simple string, file, URL, input stream, // input source or reader. Result is root node of created // tree-like structure. Single cleaner instance may be safely used // multiple times. TagNode node = cleaner.clean(...); // optionally find parts of the DOM or modify some nodes TagNode[] myNodes = node.getElementsByXXX(...); // and/or Object[] myNodes = node.evaluateXPath(xPathExpression); // and/or aNode.removeFromTree(); // and/or aNode.addAttribute(attName, attValue); // and/or aNode.removeAttribute(attName, attValue); // and/or cleaner.setInnerHtml(aNode, htmlContent); // and/or do some other tree manipulation/traversal // serialize a node to a file, output stream, DOM, JDom... new XXXSerializer(props).writeXmlXXX(aNode, ...); myJDom = new JDomSerializer(props, true).createJDom(aNode); myDom = new DomSerializer(props, true).createDOM(aNode);
    • Field Detail

      • MARKER_ATTRIBUTE

        private static final java.lang.String MARKER_ATTRIBUTE
        Marker attribute added to aid with part of the cleaning process. TODO: a non-intrusive way of doing this that does not involve modifying the source html
        See Also:
        Constant Field Values
      • HTML_4

        public static int HTML_4
      • HTML_5

        public static int HTML_5
    • Constructor Detail

      • HtmlCleaner

        public HtmlCleaner()
        Constructor - creates cleaner instance with default tag info provider,default version and default properties.
      • HtmlCleaner

        public HtmlCleaner​(ITagInfoProvider tagInfoProvider)
        Constructor - creates the instance with specified tag info provider and default properties
        Parameters:
        tagInfoProvider - Provider for tag filtering and balancing
      • HtmlCleaner

        public HtmlCleaner​(CleanerProperties properties)
        Constructor - creates the instance with default tag info provider and specified properties
        Parameters:
        properties - Properties used during parsing and serializing
      • HtmlCleaner

        public HtmlCleaner​(ITagInfoProvider tagInfoProvider,
                           CleanerProperties properties)
        Constructor - creates the instance with specified tag info provider and specified properties
        Parameters:
        tagInfoProvider - Provider for tag filtering and balancing
        properties - Properties used during parsing and serializing
    • Method Detail

      • clean

        public TagNode clean​(java.lang.String htmlContent)
      • clean

        public TagNode clean​(java.io.File file,
                             java.lang.String charset)
                      throws java.io.IOException
        Throws:
        java.io.IOException
      • clean

        public TagNode clean​(java.io.File file)
                      throws java.io.IOException
        Throws:
        java.io.IOException
      • clean

        @Deprecated
        public TagNode clean​(java.net.URL url,
                             java.lang.String charset)
                      throws java.io.IOException
        Deprecated.
        Deprecated because unmanaged network IO does not handle proxies, slow servers or broken connections well. the htmlcleaner caller should be managing the connections themselves and just providing the htmlcleaner library with a stream.
        Parameters:
        url -
        charset -
        Returns:
        Throws:
        java.io.IOException
      • clean

        @Deprecated
        public TagNode clean​(java.net.URL url)
                      throws java.io.IOException
        Deprecated.
        Creates instance from the content downloaded from specified URL. HTML encoding is resolved following the attempts in the sequence: 1. reading Content-Type response header, 2. Analyzing META tags at the beginning of the html, 3. Using platform's default charset.
        Parameters:
        url - the url to retrieve content from
        Returns:
        the cleaned content
        Throws:
        java.io.IOException
      • clean

        public TagNode clean​(java.io.InputStream in,
                             java.lang.String charset)
                      throws java.io.IOException
        Throws:
        java.io.IOException
      • clean

        public TagNode clean​(java.io.InputStream in)
                      throws java.io.IOException
        Throws:
        java.io.IOException
      • clean

        public TagNode clean​(java.io.Reader reader)
                      throws java.io.IOException
        Throws:
        java.io.IOException
      • clean

        protected TagNode clean​(java.io.Reader reader,
                                CleanTimeValues cleanTimeValues)
                         throws java.io.IOException
        Basic version of the cleaning call.
        Parameters:
        reader - (not closed)
        Returns:
        An instance of TagNode object which is the root of the XML tree.
        Throws:
        java.io.IOException
      • markNodesToPrune

        private boolean markNodesToPrune​(java.util.List nodeList,
                                         CleanTimeValues cleanTimeValues,
                                         int depth)
      • calculateRootNode

        private void calculateRootNode​(CleanTimeValues cleanTimeValues,
                                       java.util.Set<java.lang.String> namespacePrefixes)
        Assigns root node to internal variable and adds neccessery xmlns attributes if cleaner is namespace-aware. Root node of the result depends on parameter "omitHtmlEnvelope". If it is set, then first child of the body will be root node, or html will be root node otherwise.
        Parameters:
        namespacePrefixes -
      • addAttributesToTag

        private void addAttributesToTag​(TagNode tag,
                                        java.util.Map<java.lang.String,​java.lang.String> attributes)
        Add attributes from specified map to the specified tag. If some attribute already exist it is preserved.
        Parameters:
        tag -
        attributes -
      • isFatalTagSatisfied

        private boolean isFatalTagSatisfied​(TagInfo tag,
                                            CleanTimeValues cleanTimeValues)
        Checks if open fatal tag is missing if there is a fatal tag for the specified tag.
        Parameters:
        tag -
      • mustAddRequiredParent

        private boolean mustAddRequiredParent​(TagInfo tag,
                                              CleanTimeValues cleanTimeValues)
        Check if specified tag requires parent tag, but that parent tag is missing in the appropriate context.
        Parameters:
        tag -
      • newTagNode

        private TagNode newTagNode​(java.lang.String tagName)
      • createTagNode

        private TagNode createTagNode​(TagNode startTagToken)
      • isAllowedInLastOpenTag

        private boolean isAllowedInLastOpenTag​(BaseToken token,
                                               CleanTimeValues cleanTimeValues)
      • saveToLastOpenTag

        private void saveToLastOpenTag​(java.util.List nodeList,
                                       java.lang.Object tokenToAdd,
                                       CleanTimeValues cleanTimeValues)
      • isStartToken

        private boolean isStartToken​(java.lang.Object o)
      • isAllowedAsForeignMarkup

        private boolean isAllowedAsForeignMarkup​(java.lang.String tagname,
                                                 CleanTimeValues cleanTimeValues)
        Checks whether we can allow a tag as "foreign markup". This means we must have namespace aware set to true, and we must either have a current xmlns declaration within scope that isn't for HTML, or we have a namespace prefix on the tag
        Parameters:
        cleanTimeValues -
        Returns:
      • handleEndTagToken

        private void handleEndTagToken​(BaseToken token,
                                       java.util.ListIterator<BaseToken> nodeIterator,
                                       java.util.List nodeList,
                                       CleanTimeValues cleanTimeValues)
        Process rules for a new end tag token in the HTML tree.
        Parameters:
        token -
        nodeIterator -
        nodeList -
        cleanTimeValues -
      • handleStartTagToken

        private void handleStartTagToken​(BaseToken token,
                                         java.util.ListIterator<BaseToken> nodeIterator,
                                         java.util.List nodeList,
                                         CleanTimeValues cleanTimeValues)
        Processes all the rules associated with a new opening tag in the HTML tree
        Parameters:
        token -
        nodeIterator -
        nodeList -
        cleanTimeValues -
      • makeTree

        void makeTree​(java.util.List nodeList,
                      java.util.ListIterator<BaseToken> nodeIterator,
                      CleanTimeValues cleanTimeValues)
        This method generally mutates flattened list of tokens into tree structure.
        Parameters:
        nodeList -
        nodeIterator -
      • isCopiedTokenEqualToNextThreeCopiedTokens

        private static boolean isCopiedTokenEqualToNextThreeCopiedTokens​(TagNode copiedStartToken,
                                                                         java.util.ListIterator<BaseToken> nodeIterator)
        Determines if a copied token is equal to the next 3 tokens in the iterator.
      • flattenNestedList

        private java.util.List<TagNode> flattenNestedList​(java.util.List list)
        Flattens a list of tagnodes
      • areCopiedTokensEqual

        private static boolean areCopiedTokensEqual​(TagNode token1,
                                                    TagNode token2)
        Determines if two copied tokens are equal.
      • reopenBrokenNode

        private void reopenBrokenNode​(java.util.ListIterator<BaseToken> nodeIterator,
                                      TagNode toReopen,
                                      CleanTimeValues cleanTimeValues)
      • isRemovingNodeReasonablySafe

        protected boolean isRemovingNodeReasonablySafe​(TagNode startTagToken)
        Parameters:
        startTagToken -
        Returns:
        true if no id attribute or class attribute
      • createDocumentNodes

        private void createDocumentNodes​(java.util.List listNodes,
                                         CleanTimeValues cleanTimeValues)
      • closeSnippet

        private java.util.List<TagNode> closeSnippet​(java.util.List nodeList,
                                                     TagPos tagPos,
                                                     java.lang.Object toNode,
                                                     CleanTimeValues cleanTimeValues)
        Forced closing
        Parameters:
        nodeList -
        tagPos -
        toNode -
        Returns:
      • closeAll

        private void closeAll​(java.util.List nodeList,
                              CleanTimeValues cleanTimeValues)
        Close all unclosed tags if there are any.
      • addPossibleHeadCandidate

        private void addPossibleHeadCandidate​(TagInfo tagInfo,
                                              TagNode tagNode,
                                              CleanTimeValues cleanTimeValues)
        Checks if specified tag with specified info is candidate for moving to head section.
        Parameters:
        tagInfo -
        tagNode -
      • getTagInfo

        public TagInfo getTagInfo​(java.lang.String tagName,
                                  CleanTimeValues cleanTimeValues)
        Returns a TagInfo object for the specified tag name. If the tag is foreign markup, we leave it as null. This is because we may get name clashes, e.g. svg:title. However, we do handle the tag if its embedded content within the correct NS (e.g. SVG, MathML)
        Parameters:
        tagName -
        cleanTimeValues -
        Returns:
        a TagInfo object, or null if no matching TagInfo is found
      • addIfNeededToPruneSet

        private boolean addIfNeededToPruneSet​(TagNode tagNode,
                                              CleanTimeValues cleanTimeValues)
      • getAllTags

        protected java.util.Set<java.lang.String> getAllTags​(CleanTimeValues cleanTimeValues)
      • getTagInfoProvider

        public ITagInfoProvider getTagInfoProvider()
        Returns:
        ITagInfoProvider instance for this HtmlCleaner
      • getTransformations

        public CleanerTransformations getTransformations()
        Returns:
        Transformations defined for this instance of cleaner
      • getInnerHtml

        public java.lang.String getInnerHtml​(TagNode node)
        For the specified node, returns it's content as string.
        Parameters:
        node -
        Returns:
        node's content as string
      • setInnerHtml

        public void setInnerHtml​(TagNode node,
                                 java.lang.String content)
        For the specified tag node, defines it's html content. This causes cleaner to reclean given html portion and insert it inside the node instead of previous content.
        Parameters:
        node -
        content -
      • initCleanerTransformations

        public void initCleanerTransformations​(java.util.Map transInfos)
        Parameters:
        transInfos -
      • handleInterruption

        protected void handleInterruption()
        Called whenever the thread is interrupted. Currently this is a placeholder, but could hold cleanup methods and user interaction